[Long-term postoperative outcomes after surgical correction of congenital subaortic stenosis].

Objective: To analyze the results of surgical treatment of discrete subaortic stenosis and identify the main factors of left ventricular outflow tract (LVOT) restenosis in long-term postoperative period.

Material And Methods: There were 87 surgical interventions in 63 patients with congenital subaortic stenosis between 2008 and 2023. Mean preoperative peak systolic LVOT pressure gradient was 72 mmHg (50-110 mmHg). Mean age of patients before surgery was 64.3±12.6 months. Fifteen (23.8%) patients had cardiovascular comorbidities; 27 (42.8%) ones underwent previous correction of congenital heart diseases.

Results: Sixty-three (100%) patients were followed-up throughout 15 years. There was no early and long-term postoperative mortality. Redo open surgeries were performed in 17 patients. Of these, 6 patients needed for the second intervention, 1 patient - the third surgery. Actual 15-year freedom from redo surgeries was 71.7±5.8%. The following risk factors of recurrence in long-term period were found: age up to 3 years at primary surgery (OR =16.7; =0.012), systolic LVOT pressure gradient > 20 mm Hg (OR=1.21; =0.006).

Conclusion: Surgical treatment of subaortic stenosis has favorable early and long-term results with low postoperative mortality. Nevertheless, restenosis in long-term period requiring redo surgery is still a serious problem. The main risk factors of recurrent subaortic obstruction are early age and significant LVOT pressure gradient after correction. Redo surgeries should be performed irrespective of the period after the first intervention if indicated, and their incidence decreases over time.